[JDEV] GZipping Jabber Messages

Fri Jan 4 21:40:46 CST 2002

The RC4 encryption that SSL can (I think usually?) use is much less
processor intensive than compression. I don't know how it compares to
slower algorithms like 3DES or IDEA, but I would not be suprised if RC4 is
several orders of magnitude faster than gzip (LZ77+Huffman). Disregarding
one-time initialization, RC4 is a few additions, mods, and an xor; whereas
LZ77 involves all sorts of sliding frame searching I'm not familiar with
SSL's underlying protocol, maybe they screw it up, but in principle,
encrypting a byte stream should be much faster than compressing it.

I'm not trying to shoot this idea down before it's been properly discussed.
I am trying to get it properly discussed because it is an interesting
topic, and one that I think we can make some reasonable conclusions about,
based on the technical facts, without needing to write anything up
formally.

-Mike

                      Julian Missig                                                                                                    
                      <julian at jabber.or        To:       jdev at jabber.org                                                               
                      g>                       cc:                                                                                     
                      Sent by:                 Subject:  Re: [JDEV] GZipping Jabber Messages                                           
                      jdev-admin at jabber                                                                                                
                      .org                                                                                                             

                      01/04/2002 05:30                                                                                                 
                      PM                                                                                                               
                      Please respond to                                                                                                
                      jdev                                                                                                             

It's not really defining a binary transport layer, it's just gzipping
the stream. They're looking for something less processor-intensive than
SSL, I imagine.

You can argue the merits of it when/if it comes up as an official
extension/replacement for bits of Jabber via a JEP. Until then, unless
you have a better suggestion, I think they're pretty much free to play
with want they want. Maybe they'll figure out something that would be
worth writing up a JEP for. Maybe not. Official Jabber won't contain it
until they write up a JEP, so there's no need to worry.

Julian
--
email: julian at jabber.org
jabber:julian at jabber.org

Michael F Lin wrote:

> Is this in parallel to how SSL works with encryption or does SSL do
> compression already? If so then lets just use SSL. If not, then I find
the
> idea of defining our own binary transport layer a bit unsettling. We're
> talking XML, we should be above all that ;-)
>
> -Mike
>
>
>
>

>                       Julian Missig

>                       <julian at jabber.or        To:       jdev at jabber.org

>                       g>                       cc:

>                       Sent by:                 Subject:  Re: [JDEV]
GZipping Jabber Messages
>                       jdev-admin at jabber

>                       .org

>

>

>                       01/04/2002 04:57

>                       PM

>                       Please respond to

>                       jdev

>

>

>
>
>
> Nah, I think they're talking about gzipping all of the data, sending it,
> and ungzipping before sending it to the XML parser on the other side,
> just like SSL works.
>
> Julian
> --
> email: julian at jabber.org
> jabber:julian at jabber.org
>
> Michael F Lin wrote:
>
>  > Keep in mind that the gzip data would have to be base64 coded, which
>  > would increase its size by 33%. So you can run the statistics and
>  > figure out how long your payloads have to be to get better than 33%
>  > compression ratios with gzip, but I imagine it is quite long
>  > relative to the average since of a Jabber packet
>  > (message/presence/iq).
>  >
>  > -Mike
>  >
>  >
>  >
>  >
>  > Adam Theo
>  >  <adamtheo at theoret        To:       jdev <jdev at jabber.org>
>  >  ic.com>                  cc:
>  >  Sent by:                 Subject:  [JDEV] GZipping Jabber Messages
>  >  jdev-admin at jabber
>  >  .org
>  >
>  >
>  >
>  > 01/04/2002 03:32
>  >  PM
>  >  Please respond to
>  >  jdev
>  >
>  >
>  >
>  >
>  >
>  >
>  > Hi, all. There's a good discussion going on over at the DotGNU
>  > Developer list about gzip'ing the XML that is transmitted around on
>  > the DotGNU platform.
>  >
>  > Was wondering if it would be possible to incorporate the same thing
>  > for future versions of the Jabber server? Is it feasible, anyway?
>  > They are saying the trade-offs for extra resource consumption would
>  > not be bad at all if designed into the server properly, and would
>  > reduce bandwidth very dramatically (like by 80%, i think). This
>  > would be useful for high-volume servers with enough processing
>  > power, i think...

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